Geology Reports⌕ Search

SEARCH · Geology Reports

Results for “Birds”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 667 records · Page 37Linked to original sources

Bird community composition

Neotropical migrants are birds that breed in North America and winter primarily in Central and South America. Long-term population studies of birds in the Eastern United States indicated declines of some forest-dwelling birds, many of which winter in the Neotropics (Peterjohn and others 1995). These declines were attributed to loss of wintering and breeding habitat due to deforestation and fragmentation, respectively. Many species of Nearctic migrants--birds that breed in the northern regions of North America and winter in the Southern United States--are also experiencing population declines. Because large areas of undistrubed, older, bottomland hardwood forests oftern contain large numbers of habitat specialists, including forest-interior neotropical migrants and wintering Nearctic migrants, these forests may be critical in maintaining avian diversity. This study had two primary objectivs: (1) to create a baseline data set that can be used as a standard against which other bottomland hardwood forests can be compared, and (2) to establish long-term monitoring stations during both breeding and wintering seasons to discern population trends of avian species using bottomland hardwood forests.

Book chapter↗

A land manager's guide to point counts of birds in the Southeast

Current widespread concern for the status of neotropical migratory birds has sparked interest in techniques for inventorying and monitoring populations of these and other birds in southeastern forest habitats. The present guide gives detailed instructions for conducting point counts of birds. It further presents a detailed methodology for the design and conduct of inventorial and monitoring surveys based on point counts, including discussion of sample size determination, distribution of counts among habitats, cooperation among neighboring land managers, vegetation sampling, standard data format, and other topics. Appendices provide additional information, making this guide a stand-alone text for managers interested in developing inventories of bird populations on their lands.

General Technical Report↗

Tissue residues of dieldrin in relation to mortality in birds and mammals

An experiment was performed with Coturnix to learn what residue levels were indicative of death from dieldrin poisoning. Birds were fed diets containing 250, 50, 10, and 2 ppm dieldrin for periods up to 158 days. The dieldrin was 95% pure HEOD, which is 1,2,3,4,10,10-hexachloro-6, 7.epoxy. l,4,4a,5,6,7,8,8a-octahydro-l,4-endo,exo-5,8- dimethanonaphthalene. When half of a group was dead, the other half was sacrificed for comparison of residues in dead and survivors. Dosage levels controlled time to death, but did not control residue levels in the dead. Residues in liver and carcass proved to be misleading and complicated by changes in lipid content. Brain residues correlated well with death although residues in dead and survivors overlapped. Brain residues of animals killed by dieldrin in the field and in other experiments are listed. Data agree in general for several species of birds and mammals. There is evidence, however, for species differences in average lethal brain residues. It is concluded that brain residues of 4 or 5 ppm (wet weight) or higher indicate that the animal was in the known danger zone and may have died from dieldrin. Brain residues averaged lower in wild than in experimental animals. Possible explanations include species differences, more stress and exertion in the wild, and overrepresentation in the field series of individuals that will die with low but lethal brain residues. The latter is supported by the fact that the first Coturnix to die in each sex and treatment group had the lowest brain residue of its group. Birds receiving 2 ppm dieldrin, and some receiving 10 ppm, were able to maintain low brain residues throughout the experiment. However, birds of the 10 ppm group could withstand little stress and mobilization of toxicant, for a few micrograms in the brain were lethal and bodies contained hundreds or thousands of micrograms.

Book chapter↗

The North American Breeding Bird Survey

A brief history of the North American Breeding Bird Survey (BBS) and a discussion of the technique are presented. The approximately 2000 random roadside routes conducted yearly during the breeding season throughout North America produce an enormous bank of data on distribution and abundance of breeding birds with great potential use. Data on about one million total birds of 500 species per year are on computer tape to facilitate accessibility and are available to any serious investigator. The BBS includes the advantages of wide geographic coverage, sampling of most habitat types, standardization of data collection, and a relatively simple format. The Survey is limited by placement of roads (e.g., marshes and rugged mountainous areas are not well sampled), traffic noise interference in some cases and preference of some bird species for roadside habitats. These and other problems and biases of the BBS are discussed. The uniformity of the technique allows for detecting changes in populations and for creation of maps of relative abundance. Examples of each are presented.

Book chapter↗

The role of observer bias in the North American Breeding Bird Survey

Ornithologists sampling breeding bird populations are subject to a number of biases in bird recognition and identification. Using Breeding Bird Survey data, these biases are examined qualitatively and quantitatively, and their effects on counts are evaluated. Differences in hearing ability and degree of expertise are the major observer biases considered. Other, more subtle influences are also discussed, including unfamiliar species, resolution, imagination, similar songs and attitude and condition of observers. In most cases, welltrained observers are comparable in ability and their differences contribute little beyond sampling error. However, just as hearing loss can affect results, so can an unprepared observer. These biases are important because they can reduce the credibility of any bird population sampling effort. Care is advised in choosing observers and in interpreting and using results when observers of variable competence are involved.

Book chapter↗

Population dynamics of neotropical migratory birds using agriculture-forest mosaics in Campeche, Mexico

In many areas of the tropics, forests are being converted to agriculture and other uses at a rapid rate. Previous research has documented that forest-breeding migratory birds are distributed across a wide variety of habitat types during midwinter. However, to evaluate the relative importance of different habitat types to wintering birds, we need to examine habitat-specific estimates of survival. During the winter of 1992-1993, mist nets, observations of individually marked birds and point counts were used to sample bird populations in a pasture-forest mosaic in southern Mexico. Sampling was conducted four times throughout the winter on a total of six grids. Twenty nets were run for two days in each grid. A total of 129 species were captured and 3,585 individuals banded. Neotropical migrants made up 31% of the species captured and 47% of the individuals banded. The banding data were used to estimate species richness for permanent and winter residents in different habitats and at different time periods. Capture-recapture models were used to estimate overwintering survival for selected species.

Book chapter↗

The influence of capture-recapture methodology on the evolution of the North American Bird Banding Program

Capture-recapture methodology has advanced greatly in the last twenty years and is now a major factor driving the continuing evolution of the North American bird banding program. Bird banding studies are becoming more scientific with improved study designs and analytical procedures. Researchers and managers are gaining more reliable knowledge which in turn betters the conservation of migratory birds. The advances in capture-recapture methodology have benefited gamebird studies primarily, but nongame bird studies will benefit similarly as they expand greatly in the next decade. Further theoretical development of capture-recapture methodology should be encouraged, and, to maximize benefits of the methodology, work on practical applications should be increased.

Book chapter↗

Grassland birds: An overview of threats and recommended management strategies

Grassland ecosystems are dependent on periodic disturbance for habitat maintenance. Historically, grazing by native herbivores and prairie fires were the agents principally responsible for maintaining grassland areas. However, elimination of native herbivores, wide-spread fire suppression, and conversion for agriculture have greatly altered grasslands in the United States and Canada. Because of these landscape changes, many grassland birds are increasingly dependent on land managers for habitat creation, maintenance, and health. Grazing, prescribed burning, and mowing/haying are the most frequently used, and versatile, grassland management techniques. Grassland birds prefer a wide range of grass heights and densities, with some species preferring short sparse vegetation, and others preferring taller, more dense vegetation. Due to differences in species habitat preferences and regional differences in soils and floristics, the responses of individual grassland species to specific grassland management practices can be variable and often are regionally dependent. As a result, management of grassland areas is best directed toward the creation of a mosaic of grassland habitat types. This habitat mosaic is probably best maintained through some type of rotational management system in which sections of large grassland areas receive management on a regular schedule. Such a rotational system would provide a variety of habitat types in every year, would ensure the availability of suitable habitat for birds at either end of the grassland management spectrum, and also would provide habitat for birds whose preferences lie between these extremes.

Book chapter↗

Effects of urbanization on the distribution of area-sensitive forest birds in Prince George's County, Maryland

Bird survey data from Prince George's County, Maryland, were used to evaluate the effects of urbanization on the distribution of forest bird species that are area sensitive. We developed models that predict the probability of occurrence for species during the nesting season as a function of forest area and degree of urbanization. All of the 21 bird species considered occurred in a higher proportion of forests in portions of the county with low or moderate urbanization than in forests in highly urbanized areas, but species differed in their response to urbanization. We calculated the predicted probability of occurrence for each species in each forest in Prince George's County, summed the probabilities to obtain an estimate of the expected number of area-sensitive species, and integrated the expected numbers with a geographic information system coverage of Prince George's County forests to map patterns of species richness countywide. This information can be used to focus efforts to conserve habitat for area-sensitive forest birds, both in Prince George's County and throughout the Chesapeake Bay region.

Book chapter↗

Roadside versus remote: Is the habitat sampled by the Breeding Bird Survey in Maryland representative of statewide conditions?

The North American Breeding Bird Survey (BBS) has received criticism that the bird habitat sampled along the 24.5 mile long roadside transects may not be proportional to regional totals. If true, trends in bird populations recorded by the BBS may not be sensitive predictors of regional or continental change in songbird abundance. To test whether the approximately 60 BBS routes in Maryland representatively sample the state's habitat, a geographic information system (GIS) database was compiled of significant bird habitat identified from remotely sensed landcover and land-use information (e.g., Multi-Resolution Land Characteristics Consortiumclassified Landsat Thematic Mapper imagery, etc.). These GIS data layers were analyzed to determine the statewide acreage of identified habitats as well as the acreage in each of the major physiographic regions of Maryland. Regional and statewide totals were also extracted for the subsample of habitat within 30 m of the BBS transects. The results of the comparison of regional and statewide habitat totals with the BBS sample showed very low proportional difference for nearly all of the identified habitat parameters. For Maryland and perhaps other urbanizing states, the BBS provides an accurate sample of available songbird habitats.

Book chapter↗

Development of a bird banding recapture database

Recaptures (and resightings) constitute the vast majority of post-release data from banded or otherwise marked nongame birds. A powerful suite of contemporary analytical models is available for using recapture data to estimate population size, survival rates and other parameters, and many banders collect recapture data for their project specific needs. However, despite widely recognized, broader programmatic needs for more and better data, banders' recapture data are not centrally reposited and made available for use by others. To address this need, the US Bird Banding Laboratory, the Canadian Bird Banding Office and the Georgia Cooperative Fish and Wildlife Research Unit are developing a bird banding recapture database. In this poster we discuss the critical steps in developing the database, including: determining exactly which recapture data should be included; developing a standard record format and structure for the database; developing electronic means for collecting, vetting and disseminating the data; and most importantly, developing metadata descriptions and individual data set profiles to facilitate the user's selection of appropriate analytical models. We provide examples of individual data sets to be included in the database, and we assess the feasibility of developing a prescribed program for obtaining recapture data from banders who do not presently collect them. It is expected that the recapture database eventually will contain millions of records made available publicly for a variety of avian research and management purposes

Book chapter↗

Coordinating across scales: Building a regional marsh bird monitoring program from national and state Initiatives

Salt marsh breeding bird populations (rails, bitterns, sparrows, etc.) in eastern North America are high conservation priorities in need of site specific and regional monitoring designed to detect population changes over time. The present status and trends of these species are unknown but anecdotal evidence of declines in many of the species has raised conservation concerns. Most of these species are listed as conservation priorities on comprehensive wildlife plans throughout the eastern U.S. National Wildlife Refuges, National Park Service units, and other wildlife conservation areas provide important salt marsh habitat. To meet management needs for these areas, and to assist regional conservation planning, survey designs are being developed to estimate abundance and population trends for these breeding bird species. The primary purpose of this project is to develop a hierarchical sampling frame for salt marsh birds in Bird Conservation Region (BCR) 30 that will provide the ability to estimate species population abundances on 1) specific sites (i.e. National Parks and National Wildlife Refuges), 2) within states or regions, and 3) within BCR 30. The entire breeding range of Saltmarsh Sharp-tailed and Coastal Plain Swamp sparrows are within BCR 30, providing an opportunity to detect population trends within the entire breeding ranges of two priority species.

Book chapter↗

Potential environmental contaminant risks to avian species at important bird areas in the northeastern United States

Environmental contaminants, acting at molecular through population levels of biological organization, can have profound effects upon birds. A screening level risk assessment was conducted that examined potential contaminant threats at 52 Important Bird Areas (IBAs) in the northeastern Atlantic coast drainage. Using geographic information system methodology, data layers describing or integrating pollutant hazards (impaired waters, fish or wildlife consumption advisories, toxic release inventory data, estimated pesticide use and hazard) were overlaid on buffered IBA boundaries, and the relative contaminant threat for each site was ranked. The 10 sites identified as having the greatest contaminant threats included Jefferson National Forest, Stewart B. McKinney National Wildlife Refuge, Great Dismal Swamp National Wildlife Refuge, Blue Ridge Parkway, Shenandoah National Park, Adirondack Park, Edwin B. Forsythe National Wildlife Refuge, George Washington National Forest, Green Mountain National Forest, and Long Island Piping Plover Beaches. These sites accounted for over 50% of the entire study area, and in general had moderate to high percentages of impaired waters, fish consumption advisories related to mercury and PCBs, and were located in counties with substantial application rates of pesticides known to be toxic to birds. Avian species at these IBAs include Federally endangered Roseate terns (Sterna dougallii), threatened piping plovers (Charadrius melodus), neotropical migrants, Bicknell?s thrush (Catharus bicknelli), Swainson?s warbler (Limnothlypis swainsonii) and wintering brant geese (Branta bernicla). Extant data for free-ranging birds from the Contaminant Exposure and Effects--Terrestrial Vertebrates database were examined within the buffered boundaries of each IBA, and for a moderate number of sites there was qualitative concordance between the perceived risk and actual contaminant exposure data. However, several of the IBAs with substantial contaminant hazards (e.g., Blue Ridge Parkway, George Washington National Forest, Shenandoah National Park) had no recent avian ecotoxicological data. Contaminant biomonitoring is warranted at such sites, and data generated from such efforts should foster natural resource management activities.

Book chapter↗

Birds and Dutch elm disease control

Brief, factual review of information on effect of DDT and other insecticides on birds. One program for control of elm disease caused 22% decrease in number of adult birds and 56% mortality of nestlings. Quail fed 3 oz. of DDT per ton of food had 16% reduction in young hatched and 500% increase in defective chicks. Quail fed same dosage during winter and breeding seasons had 30% decrease in fertile eggs and 800% increase in defective chicks. More than 90% of their chicks died in first 6 weeks although fed no insecticide. Almost equally bad results came from feeding Pheasants diets with about 1 oz. DDT per ton. Other common insecticides (chlorinated hydrocarbons) also caused lowered chick survival and higher percentages of crippled chicks. From field data we know that 2 lbs. DDT/acre can affect birds and has even worse effects on cold-blooded animals. Efforts to control elm disease have left as much as 196 lbs. DDT/acre in top 3 inches of soil. Earthworms concentrate DDT in their tissues. Thus the treated areas can be traps for birds and other animals. What can be done? 1) In control of elm disease, use minimum effective amount of insecticide; mist blowers use less than sprayers. 2) Avoid applications during migration and nesting seasons. It has been reported that adequate control can be obtained with dormant sprays and that foliar applications may not be required. Tables of this paper show effects of DDT on reproduction of Quail, relative toxicity to quail of 8 insecticides, and amounts of 7 insecticides required to cause 40% or more decrease in Quail reproduction. These comparisons demonstrate that Aldrin, Endrin, and Dieldrin are 20 to 200 times as toxic as DDT and that Heptachlor and Chlordane are only slightly less toxic than Dieldrin. Methoxychlor and Strobane are less toxic to Quail than is DDT.

Arborist's News↗

Habitat size and bird community management

The purpose of this paper is to review the results in the literature that show the effect of area of forest on nesting migratory bird species, and to present the results of additional field work that we have conducted in forest habitats in western Maryland. These results indicate the area sensitivity of many long distance migrants. Because 80 to 95 percent of the breeding birds in the northeastern deciduous forest are neotropical migrants, the changes in bird species composition as a result of forest fragmentation can be immense. Management strategies based on habitat size are suggested to assist in maintaining communities of nesting migratory birds.

Transactions of the North American Wildlife and Na↗

North American migratory bird management issues

As human population and industry have grown in North America, land-use practices have greatly altered the landscape. As a result of this changed landscape, several migratory bird populations have declined in recent years. For waterbirds, there have been several milestones: the 1986 North American Waterfowl Management Plan (NAWMP) and the 1989 North American Wetlands Conservation Act. As a result, the United States and Canada have established 12 habitat and 2 species joint ventures. The primary emphasis of waterfowl management in Canada-U.S. has been land purchase and lease, wetland restoration, and coordination of harvest rates. Because of its different biological and cultural context, Mexico has established other conservation priorities. Mexico has had a long-standing concern to conserve its biodiversity and, in addition, conservation of Mexican resources goes hand in hand with human community development. Unlike Canada-U.S., wetland conservation projects in'Mexico include information gathering, environmental education, and management planning for its 32 priority wetlands. For migratory landbirds' scientists attribute declines in several migrant populations to forest fragmentation on the breeding grounds, deforestation on the wintering grounds, pesticide poisoning, or the cumulative effects of habitat changes. In 1990, the Neotropical Migratory Bird Conservation Program, commonly known as Partners in Flight-Aves de las Americas-was initiated. The next step that is being proposed is the formation of a habitat conservation plan for landbirds modeled after the NAWMP. Management of migratory birds requires a strong international approach in order to coordinate actions for the benefit of migratory birds, their habitats, and the uses they provide.

Wildlife Society Annual Conference↗

Bird poisoning from misuse of the carbamate Furadan in a Texas rice field

More than 100 birds consisting largely of dickcissels and savannah sparrows, as well as 9 other species of songbirds and sandpipers, died from feeding on planted rice seed treated illegally with Furadan 4F. Brain ChE activity was depressed between 32-85% in 44% of the birds. Carbofuran residues in GI tract contents of birds averaged 3.4 ppm (0.54-10 ppm). Two samples of planted rice seed contained 91 ppm and 22 ppm carbofuran. Known mortality of birds continued for about 2 weeks.

Wildlife Society Bulletin↗

Distribution and abundance of birds wintering in Maryland, 1988-1993

A winter bird survey was conducted throughout Maryland, primarily by volunteers, during the 6 winters of 1988 to 1993 between the dates of 10 Jan and 10 Feb. The state of Maryland is covered by 1231 blocks (9.5 sq. miles each), each comprising one-sixth of the standard U.S.G.S. 7.5 minute topographic quadrangle, and 548 of these blocks (44.5%) were surveyed for winter birds. Blocks were chosen in a systematic pattern with eventually almost every other block in the state having been surveyed as of Feb, 1993. Volunteers conducted each 4-hour survey by walking a 4-6 mile route chosen by the volunteer to sample habitats in proportion to their availability in the block. Surveys began around sunrise (~7:30 a.m.) and all birds seen or heard during the 4 hours were recorded on data sheets. The data were then used to create maps representing the distribution and relative abundance of each species of wintering bird found in at least 10 blocks in the state.

Maryland Birdlife↗